// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_MOJO_SERVICES_MOJO_CDM_SERVICE_H_
#define MEDIA_MOJO_SERVICES_MOJO_CDM_SERVICE_H_

#include <stdint.h>

#include <memory>

#include "base/callback.h"
#include "base/compiler_specific.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/memory/weak_ptr.h"
#include "media/base/content_decryption_module.h"
#include "media/base/eme_constants.h"
#include "media/mojo/interfaces/content_decryption_module.mojom.h"
#include "media/mojo/services/media_mojo_export.h"
#include "media/mojo/services/mojo_cdm_promise.h"
#include "media/mojo/services/mojo_cdm_service_context.h"
#include "media/mojo/services/mojo_decryptor_service.h"

namespace media {

class CdmFactory;

// A mojom::ContentDecryptionModule implementation backed by a
// media::ContentDecryptionModule.
class MEDIA_MOJO_EXPORT MojoCdmService
    : NON_EXPORTED_BASE(public mojom::ContentDecryptionModule) {
public:
    // Get the CDM associated with |cdm_id|, which is unique per process.
    // Can be called on any thread. The returned CDM is not guaranteed to be
    // thread safe.
    // Note: This provides a generic hack to get the CDM in the process where
    // MediaService is running, regardless of which render process or
    // render frame the caller is associated with. In the future, we should move
    // all out-of-process media players into the MediaService so that we can use
    // MojoCdmServiceContext (per render frame) to get the CDM.
    static scoped_refptr<::media::ContentDecryptionModule> LegacyGetCdm(
        int cdm_id);

    // Constructs a MojoCdmService and strongly binds it to the |request|.
    MojoCdmService(base::WeakPtr<MojoCdmServiceContext> context,
        CdmFactory* cdm_factory);

    ~MojoCdmService() final;

    // mojom::ContentDecryptionModule implementation.
    void SetClient(mojom::ContentDecryptionModuleClientPtr client) final;
    void Initialize(const std::string& key_system,
        const std::string& security_origin,
        mojom::CdmConfigPtr cdm_config,
        const InitializeCallback& callback) final;
    void SetServerCertificate(const std::vector<uint8_t>& certificate_data,
        const SetServerCertificateCallback& callback) final;
    void CreateSessionAndGenerateRequest(
        CdmSessionType session_type,
        EmeInitDataType init_data_type,
        const std::vector<uint8_t>& init_data,
        const CreateSessionAndGenerateRequestCallback& callback) final;
    void LoadSession(CdmSessionType session_type,
        const std::string& session_id,
        const LoadSessionCallback& callback) final;
    void UpdateSession(const std::string& session_id,
        const std::vector<uint8_t>& response,
        const UpdateSessionCallback& callback) final;
    void CloseSession(const std::string& session_id,
        const CloseSessionCallback& callback) final;
    void RemoveSession(const std::string& session_id,
        const RemoveSessionCallback& callback) final;

    // Get CDM to be used by the media pipeline.
    scoped_refptr<::media::ContentDecryptionModule> GetCdm();

private:
    // Callback for CdmFactory::Create().
    void OnCdmCreated(const InitializeCallback& callback,
        const scoped_refptr<::media::ContentDecryptionModule>& cdm,
        const std::string& error_message);

    // Callbacks for firing session events.
    void OnSessionMessage(
        const std::string& session_id,
        ::media::ContentDecryptionModule::MessageType message_type,
        const std::vector<uint8_t>& message);
    void OnSessionKeysChange(const std::string& session_id,
        bool has_additional_usable_key,
        CdmKeysInfo keys_info);
    void OnSessionExpirationUpdate(const std::string& session_id,
        base::Time new_expiry_time);
    void OnSessionClosed(const std::string& session_id);

    // Callback for when |decryptor_| loses connectivity.
    void OnDecryptorConnectionError();

    // CDM ID to be assigned to the next successfully initialized CDM. This ID is
    // unique per process. It will be used to locate the CDM by the media players
    // living in the same process.
    static int next_cdm_id_;

    base::WeakPtr<MojoCdmServiceContext> context_;

    CdmFactory* cdm_factory_;
    scoped_refptr<::media::ContentDecryptionModule> cdm_;

    std::unique_ptr<MojoDecryptorService> decryptor_;

    // Set to a valid CDM ID if the |cdm_| is successfully created.
    int cdm_id_;

    mojom::ContentDecryptionModuleClientPtr client_;

    base::WeakPtr<MojoCdmService> weak_this_;
    base::WeakPtrFactory<MojoCdmService> weak_factory_;

    DISALLOW_COPY_AND_ASSIGN(MojoCdmService);
};

} // namespace media

#endif // MEDIA_MOJO_SERVICES_MOJO_CDM_SERVICE_H_
